Washington has delivered complaints to Moscow about accusations of increasing intimidation of US diplomats in Russia, the State Department said.
"We see an increase and we take it seriously," State Department spokeswoman Elizabeth Trudeau told reporters at a press briefing.
Secretary of State John Kerry last discussed the matter with Russian President Vladimir Putin on March 24, CNN reported citing Trudeau as saying.
He said that harassment of diplomats by Russian security agents and traffic police had been an issue over the past two years but did not detail any incidents nor why Kerry brought up the matter with Putin.
Other Western embassies had reported the same behaviour toward their diplomats stationed in Moscow, Trudeau added.
However, Moscow has charged that Washington has also engaged in problematic behaviour.
Last week, the Russian Foreign Ministry Spokeswoman Maria Zakharova said that Moscow has "felt a significant increase in pressure on the Russian Embassy and consulates general of our country in the US."